19] It is believed to be an
idealised version of a real conversation with Madame de Broglie, and was
first printed, almost as soon as written (1777), in the correspondence
in which Metra, in imitation of Grimm, informed a circle of foreign
subscribers what was going on in Paris. The admirers of Diderot profess
to look on this Conversation as one of the most precious pearls in his
philosophic casket. It turns upon the conditions of belief and unbelief,
represented by the two interlocutors respectively, and is a terse and
graphic summary of the rationalistic objections to the creed of the
church. The most conspicuous literary passage in it is a parable which
has been attributed to Rousseau, but with which Rousseau had really
nothing to do, beyond reproducing the spirit of its argument in the ever
famous creed of the Savoyard Vicar.

[219] _Ib._ ii. 505-528.

A young Mexican, tired of his work, was sauntering one day on the
seashore. He spied a plank, with one end resting on the land, and
the other dipping into the water. He sat down on the plank, and
there gazing over the vast space that lay spread out before him, he
said to himself: "It is certain that my old grandmother is talking
nonsense, with her history of I know not what inhabitants, who, at
I know not what time, landed here from I know not where, from some
country far beyond our seas. It is against common sense: do I not
see the ocean touch the line of the sky? And can I believe, against
the evidence of my senses, an old fable of which nobody knows the
date, which everybody arranges according to his fancy, and which is
only a tissue of absurdities, about which people are ready to tear
out one another's eyes." As he was reasoning in this way, the
waters rocked him gently on his plank, and he fell asleep. As he
slept, the wind rose, the waves carried away the plank on which he
was stretched out, and behold our youthful reasoner embarked on a
voyage.

_La Marechale._--Alas, that is the image of all of us; we are each
on our plank; the wind blows, and the flood carries us away.

_C._--He was already far from the mainland when he awoke. No one
was ever so surprised as our young Mexican, to find himself out on
the open sea, and he was mightily surprised, too, when having lost
from sight the shore on which he had been idly walking only an
instan